Turbine-governing mechanism.



1', 1101111111111011. TUBBINE QOVEBNING MEOHANISM. APIiLIOATION FILEDJUNE 18, 1906 M161 Jan. 31,1911.

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WITNESSES:

INVENTgR i I BY ATTORNEY UNITED STATES PATENT OFFICE.

FRANCIS HODGKINSON, OF EDGEWOOD PARK, PENNSYLVANIA, ASSIGNOR TO THEWESTINGHOUSE MACHINE COMPANY, A CORPORATION OF PENNSYLVANIA.

TURBINE-GOVERNING MECHANISM.

Specification of Letters Patent. Patented Jan, 31, 1911 Applicationfiled June 16, 1906. Serial No. 322,028.

T 0 all whom it may concern:

Be it known that I, FRANCIS I-Iooonmso'x, a subject of the King of GreatBritain and Ireland, residing at Edgew'ood Park, in the county ofAllegheny and State of Pennsylvania, have made a new and usefulInvention in Turbine-Governing Mechanism, of which the following is aspecification.

This invention relates to elastic fluid tur; bines and more particularlyto governing means for turbines.

Elastic fluid turbines are ordinarily provided with extremely sensitivespeed governors, or controlling devices, which operate in conjunctionwith more or less complicated valve-operating mechanisms and proportionthe amount of motive fluid supplied to the turbine in accordance withthe load demand. The valve-actuating mechanism is usually controlled bythe governor through a fluid or electrically actuated relay device andWhile it is ordinarily reliable and accurate in operation, it isexpensive to build and diflicult to adjust.

The object of this invention is, therefore, the production of agoverning mechanism for turbines which is of simple construction andextremely sensitive and effective in operation.

A further object is the production of a mechanically actuated governorcontrolled valve-operating mechanism for turbines.

The invention, broadly, consists of a 1nechanically-actuated governingmechanism which operates in conjunction with the primary and secondaryvalves of a turbine and is adapted to admit motive fluid to the turbineperiodically or in puffs; the amounts of fluid admitted, or the durationof the puffs, being proportioned in accordance with the load-demand. Thegoverning and valveoperating mechanisms are so arranged that the primaryvalve will admit motive fluid in regulablo amounts to the initial orprimary stage of the turbine while the turbine is operating under normalloads and the secondary valve will operate in conjunction with theprimary valve and admit motive fluid to a secondary stage of the turbineWhile the turbine is operating under excessive loads.

In the drawings accompanying this application and forming a partthereof, Figure 1 is a plan view of a turbine equipped with a governingmechanism embodying my invention; Fig. 2 is a somewhat diagrammatic Viewof a valve-operating mechanism in conjunction with a controllinggovernor; Fig. 3 is a partial plan view of the apparatus shown in Fig.2; Fig. at is a section along the line 5-5 of Fig. 2; and Figs. 5, 6

and 7 illustrate diagrammatically the operation of the valve-operatingmechanism.

A turbine 6 is provided with a primary admission port 7, whichcommunicates with an initial stage of the turbine, and a secondaryadmission port 8, which communicates with a secondary stage of theturbine. The primary and secondary admission ports are provided withautomaticallyarctuated valves which are operated by a system ofeccentrics, links and levers and are adapted to admit motive fluid tothe turbine in accordance with the load demand.

The primary admission port 7 is provided with a valve 10 and a valvecasing 11, formed integrally with the casing of the turbine, theinterior passages of which communicate with a source of motive fluidsupply. A piston 15, rigidly mounted on the stem 13, operates in acylinder 16, located above the valve casing 11., and performing thefunction of an air dash-pot. A helical spring 17 mounted between thepiston 15 and the end wall of the cylinder surrounds the stem 13 and isadapted to force the valve 10 against its seat and close the primaryadmission port. A chamber 21 is interposed between the valve casing 11and the cylinder 16 and is provided with an exhaust port 21 which isadapted to discharge into the atmosphere the motive fluid leakingthrough the gland 14; and thereby prevent fluid pressure from piling upunder the piston 15 and raising the valve 10.

A bifurcated lever 18 is provided with an extending arm 22, which isforked at the end, and is fulcrumed on a shaft 1!), which is mounted ona suitable bracket 20, formed integrally with the walls of the cylinder16. The valve stem 13 is provided with integrally-formed collars 23which operate in conjunction with, and are located at either side of theforked end of the arm 22.

Three levers 24, 25 and 26 are tlulcrumed on the shaft 19 and arerespectively oscillated by eccentrics 27, 2S and 29, which are mountedon a rotatable shaft 31 journaled on the casing of the turbine anddriven by the turbine shaft 32 through suitable gears.

Each of the levers 24, 25 and 26 is pro vided with a pivotally-mountedhook 33 which is provided with a controlling spring 30 and which, forcertain positions of its supporting lever, is adapted to seize thebifurcated lever 18 and raise the valve 10, through the agency of theforked arm 22 and the valve stem 13, and admit motive fluid to theinitial stage of the turbine.

The operating eccentrics 27, 28 and 29 are 120 apart on the shaft 31 andthe hooks 33 are adapted to successively seize the lever 18 and open thevalve 10; the amount of port opening being proportioned by the speed ofthe turbine.

A governor-actuated cam 34 is mounted on the hub portion of each of thelovers 24, 25 and 26 and each cam is provided with an arm 35, to whichan adjustable rod 36 is pivotally connected. The rods 36 are connectedby suitable levers to a shaft 37 which is actuated by a speed-responsivegovernor 38 through suitable links and levers.

The governor 38 consists of fly-balls 39, pivotally mounted on brackets,(not shown) which are rigidly mounted on a rotatable standard 41. Thestandard 41 is provided with suitable gears, (not shown), which meshwith a worm 42, formed on the shaft 32 of the turbine. A reciprocatingsleeve 43 surrounding the standard 41 is actuated by the fly-balls 39and is adapted to occupy different positions along the shaftcorresponding to different speeds of the turbine.

The shaft 37 is operated by the reciprocating sleeve 43 through suitablelinks and levers, diagrannnatically illustrated in Fig. 2 by the lever44, and is adapted to vary the positions of the cams 34 relative totheir corresponding supporting levers.

Each hook 33 is adapted, when in its lowest position, to seize the lever18, and the levers 24, 25 and 26 are arranged to move theircorresponding hooks sufficiently' to open the initial valve 10 a maximumamount. Each cam 34 is moved by the governor, during light or normalloads on the turbine, to such positions that it will contact with itscorresponding hook 33 at some point during the forward travel of thehook, release the lever 18 and permit the closing of the valve 10,thereby m'oportioning the periodic port opening of the valve inaccordance with the load demand. At excessive speeds of the turbine thecams 34 are moved by the governor to such positions that the hooks 33,during their reciprocations, are rendered ineffective and the valvesremain closed.

The operation of the valve is diagrammatically illustrated in Figs. 5, 6and 7, in which the different positions, of the eccentrics are shown. InFig. 5 the eccentric 27 is shown in the position at which itscorresponding hook 33 seizes the lever 18 and r starts to open the valve10. At exceedingly light loads, the cam 34, corresponding to the lever24, which is actuated by the eccentric 27 will knock off itscorresponding hook 33 and releases the lever 18 at some position of theeccentrics travel, as illustrated in Fig. 2, and the valve 10 will dropthe distance 48, through which it has traveled, and close the port 7 Theport 7 will remain closed until the eccentric 28 has moved through theare 4950, or until the lever 25, which is actuated by the eccentric 28,moves to such a position that its hook 33 will seize the lever 18 andopen the valve. As the load on the turbine increases, the periodic portopening of the valve increases and the time the valve remains seated isdecreased until at some predetermined load on the turbine thegovernor-actuated cams 34 are moved to such positions that the lever 18is released by one hook 33 at an eccentric position corresponding to thepositions of the eccentric 27, as illustrated in Fig. 7 and the valve 10on reaching its seat is immediately raised by the hook 33 of theeccentric 28. As the load continues to increase, the valve 10 is raisedgreater amounts by the valveoperating mechanism and when released by thegovernor-actuated cams does not reach its seat but is caught by the nexthook 33 and again raised a predetermined amount. The governor-actuatedcams are moved by the governor during increasing loads to such positionsthat the time of releasing the lever 18 during the eccentric stroke isretarded until at some load .on the turbine, (about full load) the camsare moved to such positions that they do not contact with the hooks 33or release the valve 10 and the valve 10, as illustrated in Fig. 7 israised by each hook, while its corresponding eccentric moves from 51 to52, and then lowered, while the eccentric travels from 52 to v53, atwhich point the descending lever 18 is seized by the hook 33 of the nexteccentric which then occupies the position 51 and the valve will beagain raised and will continue to oscillate between three-fourths andmaximum cutoff until the load decreases. At about full load, or when theprimary valve is oscillating between maximum and three-fourths portopening, the secondary valve begins to admit motive fluid to a secondarystage of the turbine through the port 8. The valve-operating mechanismof the secondary valve is similar to the operating mechanism of theprimary valve, except that the cams 34 are adapted to hold the hooks 33in an inoperative position so that they do not open the secondary valveuntil the primary valve is admitting a maximum amount of motive fluid tothe turbine. As the load on the turbine continues to increase past fullload, the

cams 34 of the secondary valve mechanism move to such a position thatthe periodic port openings of the valve increase in accordance with theload demand. At a predetermined and excessive load on the turbine, thesecondaryvalve, like the primary valve, will be continuously open, butwill oscillate between three-fourths and maximum port openin Theposition of the controlling cams 3% may be readily adjusted bylengthening or shortening the connecting rods 36 and the throw of thevalve disk 12 varied accord ingly, and various means may be utilized inconnection with the valve stem to close the valve after the lever 18 isreleased by the hooks 33.

It is apparent that the amount of motive fluid admitted to the turbineis proportioned by the governor 38 in accordance with the speed of theturbine, and that practically unlimited power is available for operatingthe valves and consequently they will operate effectively with no dangerof sticking or becoming inoperative.

What I claim is:

1. In combination with the primary and secondary valve of a steamturbine, a valveoperating mechanism comprising a primary and secondaryvalve-actuating lever, a system of oscillating levers provided withhooks for seizing said actuating levers and opening said valves, agovernor-controlled means for contacting with said hooks and releasingsaid actuating levers to close said valves, thereby proportioning theport opening of the valves in accordance with the load demand.

2. In combination with the primary and secondary valve of a steamturbine, a valveoperating mechanism comprising a system of oscillatinglevers, an actuating lever for each of said valves, hooks carried bysaid oscillating levers for seizing said actuating levers and openingsaid valves, and governor-controlled means whereby one or both of saidvalves is rendered operative or inoperative.

3. In combination with the primary and secondary valves of a turbine,means positively actuated by the turbine rotor for openmg each valve andmechanisms responsive to variations of speed of the turbine fordisengaging said means and thereby proportioning the delivery of fluidto the turbine in accordance with the speed of the turbine.

4. In combination with the primary and secondary valves of a steamturbine, means positively actuated by the turbine rotor for controllingthe operation of said valves by periodically engaging therewith andmechanisms actuated by the turbine governor for disengaging said meansand thereby timing the operation of said valves.

5. In combination with the primary and secondary valves of a steamturbine, means positively actuated by the turbine rotor for engagingwith and periodically opening each of said valves and mechanismsactuated by the turbine governor for timing the ope a tion of said meanswhereby one or both of said valves are rendered inoperative.

6. In combination with the primary and secondary valves of a steamturbine, means positively actuated by the turbine rotor for periodicallyengaging .with and actuating each of said valves and a timing deviceactuated by the turbine governor for controlling the operation of saidmeans whereby the delivery ot' motive fluid is controlled in accordancewith the load demand and the secondary valve is rendered inoperativeuntil the primary valve is delivering a maximum amount of fluid to saidturbine.

7. In combination with the primary and secondary valves of a turbine, avalve operating mechanism comprising a valve operating lever for each ofsaid valves, a system of oscillating hooks engaging each of said valvesand governor controlled means for timing the operation of each of saidhooks and thereby controlling the operation of said valves.

8. In combination with the primary and secondary valves of a turbine,means positively actuated by the turbine rotor for peri odically openingeach of said valves and mechanisms controlled by the turbine governorfor controlling the operation of said means and thereby proportioningthe delivery of motive fluid to the turbine in accordance with the loaddemand.

9. In a governing mechanism for an elastic fluid turbine, a valve and avalve operating mechanism comprising a valve operating lever, a seriesof hooks adapted to successively engage said lever and open said valve,a governor controlled timing device for disengaging said hooks andthereby proportioning the port opening of said valve in accordance withthe speed of the turbine.

10. In combination with the primary and secondary valves of a steamturbine, a valve operating mechanism comprising a valve operating leverfor each of said. valves, a system of oscillating hooks adapted tosuecessively engage said lever and open said valve and a governorcontrolled timing device for disengaging each of said hooks and therebytiming the operation of said valves.

11. In a governing mechanism for an elastice fluid turbine, a valve anda valve operating mechanism comprising a valve operating lever, a seriesof hooks adapted to suecessively engage said lever whereby said valve isperiodically opened and a governor controlled timing device fordisengaging said hooks and thereby controlling the operation of saidvalves.

12. In an elastic fluid turbine, in combination with the primary andsecondary &

valves thereof, a mechanically actuated valve operating mechanism foreach valve, and means dependent on the speed of the turbine forcontrolling the operation of each valve operating mechanism.

13. In an elastic fluid turbine, in combination With the primary andsecondary valves of the turbine, a valve operating mechanism for eachvalve, rotatable means for actuating said mechanisms to pulsate saidvalves, and means dependent on the speed of the turbine for controllingthe operation oi said valve operating mechanisms.

let. In an elastic fluid turbine, a primary and a secondary valve, anactuating hook for each valve, an eccentric for actuating each hook andspeed responsive means for controlling the operations of said hooks.

15. In an elastic fluid turbine, primary and secondary valves, valveoperating mechanism for each valve, eccentrically operated mechanismsfor said valve operating mechanisms, and means dependent on the speed ofthe turbine for controlling the operation of said valve operatingmechanisms.

16. In combination with the primary and secondary valves of a turbine,separate valve operating mechanism positively actuated by the turbinerotor for periodically opening each valve and means actuated by theturbine governor for timing the operation of said mechanisms whereby onemechanism is rendered ineffective for opening its corresponding valveuntil the other valve is delivering a maximum amount of motive fluidtothe turbine.

17. In combmatlon With the prnnary and secondary valves of a turbine,valve operating mechanisms positively actuated by the turbine rotor foropening said valves and means actuated by the turbine governor fortiming the operation of said valves, operating mechanism whereby onevalve is held closed until the other valve is delivering a maximumamount of motive fluid to the turbine.

18. In combination With the primary and secondary valves of a turbine, avalve operating mechanism comprising a system of oscillating hooks and agovernor controlled timing device for each valve for controlling theoperation of said hooks and thereby controlling the operation of saidvalves.

19. In combination with the primary and secondary valves of a turbine, avalve operating mechanism for each valve comprising oscillating hooksand a governor controlled timing device for timing the operation of saidhooks whereby one valve operating mechanism is rendered ineffective foropening its corresponding valve until the other valve is delivering amaximum amount of steam to the turbine. a

20. In a turbine, a valve and a valve operating mechanism comprisingaseries of: oscillating hooks for successively opening said valve, theopening movement of one hook overlapping the opening movement of anotherhook of said series.

In testimony whereof, I have hereunto subscribed my name this 1 1th dayof June,

FRANCIS HODG'KINSON. itnesses CHARLES W. MoGI-IEE, E. V. MoCALLIsTER.

